1. Field of the Invention
The present invention relates to a piperidine derivative and a process for preparing the same. More particularly, the present invention relates to a piperidine derivative useful as an intermediate for pharmaceuticals such as paroxetine and the like which are useful, for example, as an antidepressant.
2. Discussion of the Related Art
In general, paroxetine useful as an antidepressant is prepared by the processes described, for example, in Japanese Unexamined Patent Publication No. 7-138228 and Japanese Examined Patent Publication No. 59-46216.
However, these processes have the drawback that, upon deprotection of N-methyl group, complicated procedures such as hydrolysis after the transformation of N-methyl group to carbamate group are required.
In addition, there is disclosed a process for preparing paroxetine using an amidomalonic acid ester derivative as a starting material in, for example, Japanese Unexamined Patent Publication No. 7-138228. However, the amidomalonic acid ester derivative is not in general commercially available. Therefore, there necessitates troublesome procedures such that the amidomalonic acid ester derivative should be previously prepared before using.
An object of the present invention is to provide a compound useful as an intermediate for preparing paroxetine and a process for simply and industrially preparing the compound.
These and other objects of the present invention will be apparent from the following description.